Finding the Fourth Proportional to 16,815.80, 25,174.72 and 13,106.72

Step by Step Solution

1. Step 1: Write the proportion equation
   16,815.80 : 25,174.72 = 13,106.72 : x
2. Step 2: Convert to fraction form
   16,815.80/25,174.72 = 13,106.72/x
3. Step 3: Cross multiply
   16,815.80x = 25,174.72 × 13,106.72
4. Step 4: Simplify right side
   16,815.80x = 329,958,006.12
5. Step 5: Solve for x
   x = 329,958,006.12/16,815.80
6. Step 6: Final answer
   x = 19,621.90